1. Field of the Invention
This invention relates to a method for removing a top tape from a chip tape with which small-sized electronic circuit elements are charged and a device therefor, and more particularly to a method and a device for removal of a top tape from a chip tape with high accuracy and good efficiency before picking up the circuit elements from the chip tape, which facilitates disposal of the removed top tape.
2. Description of the Prior Art
A chip tape is extensively used in electronics industries. The chip tape comprises a tape such as a cardboard tape, an embossed plastic tape or the like charged with various kinds of small-sized electronic circuit elements (hereinafter referred to as "chips") at regular intervals.
The chip tape, as shown in FIG. 1 wherein the chip tape is generally indicated by reference character A, typically comprises a main tape element 1 formed of a cardboard of a small width and a continuous length and provided with chip receiving holes 2 and pitch holes 3 at uniform intervals, and a top tape element 4 and a bottom tape element arranged on surfaces of the main tape element 1 to seal the chip receiving holes 2 teerebetween along lines 5 which have chips t charged therein. The main tape element 1 may be formed of a plastic material, and the chip receiving holes 2 may be formed by embossing.
The chip tape A of a continuous length is wound into a reel-like shape and then received in a chip tape cassette. The chip tape A, as shown in FIG. 5, is then driven by successively engaging the pitch holes 3 with a suitable means such as a ratchet 6, a pawl lever 7 or the like, and is intermittently fed from the cassette by a predetermined length. Subsequently, the top tape element 4 is peeled from the main tape element 1 to successively expose the chips t received in the chip receiving holes 2, which are then taken out from the holes 2 in order by a suction head of an automatic chip mounting apparatus or the like and transferred to a subsequent chip mounting step.
Extraction of the chips t from the chip tape A requires peeling of the top tape element from the main tape element.
Conventionally, the peeling is carried out by manually peeling a leading portion of the top tape element 4 by a predetermined length and winding the peeled leading end on a take-up reel 8. The reel 8 is then rotated in synchronism with feeding of the chip tape A to accomplish peeling of the top tape element 4 from the main tape element 1 as well as winding of the main tape element 1 free of the top tape element 4. Alternatively, the peeling may be carried out utilizing by tension exerted by a pair of pressure feed rollers 9.
However, it was found that such conventional peeling as described above exhibits the following disadvantages.
One disadvantage is that replacement of the chip tape cassette or reel is highly troublesome and requires much time, because it needs operation of manually peeling the initial or leading end of the top tape and then winding the end on the take-up reel 8.
Another disadvantage encountered with the conventional peeling is that it requires to arranging the take-up reel 8 or a pair of the pressure feed rollers 9 so that it may be driven in synchronism with feeding of the chip tape A. As a result, it requires a sufficient space. Also, it is troublesome to adjust timing of the peeling and force required therefor, which causes problems such as a failure in the peeling, breakage of the top tape element and the like, and temporary interruption of an automatic chip mounting apparatus.
A further problem in the conventional peeling is that it requires disposal of the peeled top tape element such as the removal from the take-up reel by cutting or the like.